issues of rape and guilt appear to be ambiguous
It seems to me that the issue of whether Susie is actually raped in the motel and the issue of whether Sanchez is actually guilty of the murder are both left open, likely deliberately (the cops could have simply beaten a false confession out of Sanchez.) The open issues of crime and guilt,with the loose ends not truly being tied up mirror life in the real world and make this a very modern or timeless film, as opposed to a dated one.
Recall that Linnekar's daughter gets to leave with her expensive lawyer without being questioned. To me that suggests that she could be the true murderer and if so, can get away with it because of her wealth. These issues remain hanging after the final credits.